You might think: a bunch of moisture inside a fabric tent - will mold build up? Well, we thought of that too - so we made the fabric to be antimicrobial in order to prevent mold or bacteria build up. Just wipe down the walls after use with a towel, let the Saunabox air out, and throw your absorbent mat in the washer/dryer. Use non-toxic cleaner on the floor of the inside and you're all set!